Ni/Al_2O_3催化剂上CH_4部分氧化制合成气机理的IR研究(英文)

在２．９％（ｗｔ）Ｎｉ／Ａｌ２Ｏ３催化剂上用ｉｎｓｉｔｕＦＴＩＲ研究了ＣＨ４部分氧化制合成气的反应机理。结果表明，催化剂表面的活性碳物种与化学吸附的Ｏ原子反应生成ＣＯ；ＣＨ４／Ｏ２（２：ｌ）混合气在催化剂表面吸附的ＩＲ谱图表明只有Ｈ２Ｏ和ＣＯ２存在，说明ＣＨ４和ＣＯ２的重整反应没有发生。因此，我们认为ＣＯ和Ｈ２是一级产物。     

Rapid Determination of Polyphenols in Tobacco by MLC

A rapid, simple and reliable analytical procedure has been developed for the determination of polyphenols, including chlorogenic acid, rutin and scopoletin, in tobacco samples. After extraction, the polyphenols were analyzed by micellar liquid chromatography coupled with UV detection at 340 nm without sample preparation step. The compositions of the micellar mobile phase for the separation of these polyphenols were selected adequately by a chemometric method. The optimal resolution and satisfactory peak shapes were achieved with 0.022 mol L^?1 sodium dodecyl sulfate and 0.45% (volume fraction) 1-propanol solution at pH 5.0 using Eclipse XDB-C18 (250 mm × 3.0 mm, 5 μm) column. The limits of detection for chlorogenic acid, rutin and scopoletin were 0.15, 0.29 and 0.22 μg mL^?1, respectively. This validated method was successfully applied to qualitatively and quantitatively analyze the polyphenols in tobacco in less than 10 min.     

Recovering Ga(III) from coordination complexes using pyridine 2,6‐dicarboxylic acid chelation ion chromatography

Ion exchange chelation chromatography is an effective means to extract metals from coordination complexes and biological samples; however there is a lack of data to verify the nature of metal complexes that can be successfully analysed using such a procedure. The aim of this study was to assess the capability of pyridine 2,6‐dicarboxylic acid (PDCA) to extract and quantify Ga(III) from a range of environments using standard liquid chromatography apparatus. The PDCA chelation method generated a single Ga(III) peak with a retention time of 2.55 ± 0.02 min, a precision of <2% and a limit of detection of 110 μM. Ga(III) hydroxide complexes (highest stability constant 15.66) were used to successfully cross‐validate the chelation method with inductively coupled plasma mass spectrometry. The PDCA assay extracted 96.9 ± 1.2% of the spiked Ga(III) from porcine mucus and 100.7 ± 2.7% from a citrate complex (stability constant 10.02), but only ca 50% from an EDTA complex (stability constant 22.01). These data suggest that PDCA chelation can be considered a suitable alternative to inductively coupled plasma mass spectrometry for Ga(III) quantification from all but the most strongly bound coordinated complexes i.e. a stability constant of <15. Copyright © 2010 John Wiley & Sons, Ltd.     

全二维气相色谱/飞行时间质谱用于莪术挥发油分离分析特性的研究

用全二维气相色谱 /飞行时间质谱 (GC×GC/TOFMS)研究莪术挥发油。对GC×GC与GC的分离特性和GC×GC/TOFMS与GC/MS的定性能力进行了比较。在相同条件下 ,GC分离出 87个峰 ,GC×GC分出约 5 0 0个峰 ,GC/MS和GC×GC/TOFMS鉴定出匹配度大于 80 0的组分分别为 4 6种和 2 2 7种。除此之外 ,GC×GC/TOFMS对每一个组分可给出三维定性信息 ,定性可靠性大大提高。研究结果显示与传统的分析技术相比 ,GC×GC/TOFMS在中药挥发油成分分析领域有很大的优势     

溶胶-凝胶法制备二元稀土掺杂(Sm2O3)0.04 (Gd2O3)0.06 Ce0.8O2-δ纳米粉体

以Sm2O3、Gd2O3与Ce2(CO3)3.nH2O为原料,采用Sol-Gel法制备了二元稀土掺杂(Sm2O3)0.04(Gd2O3)0.06Ce0.8O2.δ纳米粉体.测定了pH值对0.80Ce(OH)4·0.08Sm(OH)3·0.12Gd(OH)3水溶胶体系zeta电位的影响.pH值约为7.0时,体系的Zeta电位为0,即体系的等电点(IEP)为7.0.pH值为10.0时,Zeta电位达到最大值-18.5my,说明此时该体系的稳定性最好.DTA/TG热分析表明,0.80Ce(OH)4·0.08Sm(OH)3·0.12Gd(OH)3粉体的热分解温度约为232℃.由粉末XRD分析可知,经750℃焙烧的二元稀土掺杂CeO2粉末为立方萤石结构,说明Sm2O3与Gd2O3已完全固溶到CeO2中形成了CeO2基固溶体.由TEM照片可以看出,粉末具有良好的分散性,呈软团聚状态,粒径在5-10nm之间.经BET测试计算的平均颗粒尺寸为11nm,与TEM结果是一致的.     

A practical strategy for the characterization of coumarins in Radix Glehniae by liquid chromatography coupled with triple quadrupole-linear ion trap mass spectrometry

The aim of the present study was to develop a practical method for the characterization of coumarins in Radix Glehniae by liquid chromatography–mass spectrometry (LC–MS). First, 10 coumarin standards (including two pairs of isomers) were studied, and mass spectrometry fragmentation patterns and elution time rules for the coumarins were found. Then, an extract of Radix Glehniae was analyzed by the combination of two scan modes, i.e., multiple ion monitoring-information-dependent acquisition-enhanced product ion mode (MIM-IDA-EPI) and precursor scan information-dependent acquisition-enhanced product ion mode (PREC-IDA-EPI) on a hybrid triple quadrupole-linear ion trap mass spectrometer. A total of 41 coumarins were identified on the basis of their mass spectrometry fragmentation patterns. This is the first time that these two scan modes have been combined to characterize chemical constituents in traditional Chinese medicine. This new method allowed the identification of coumarins in Radix Glehniae in trace amounts. The methodology proposed in this study could be valuable for the structural characterization of coumarins from complex natural and synthetic sources.     

An automatic system for multidimensional integrated protein chromatography

An automatic system for multidimensional integrated protein chromatography was designed for simultaneous separation of multiple proteins from complex mixtures, such as human plasma and tissue lysates. This computer-controlled system integrates several chromatographic columns that work independently or cooperatively with one another to achieve efficient high throughputs. The pipelines can be automatically switched either to another column or to a collection container for each UV-detected elution fraction. Environmental contamination is avoided due to the closed fluid paths and elimination of manual column change. This novel system was successfully used for simultaneous preparation of five proteins from the precipitate of human plasma fraction IV (fraction IV). The system involved gel filtration, ion exchange, hydrophobic interaction, and heparin affinity chromatography. Human serum albumin (HSA), transferrin (Tf), antithrombin-III (AT-III), alpha 1-antitrypsin (α1-AT), and haptoglobin (Hp) were purified within 3 h. The following recovery and purity were achieved: 95% (RSD, 2.8%) and 95% for HSA, 80% (RSD, 2.0%) and 99% for Tf, 70% (RSD, 2.1%) and 99% for AT-III, 65% (RSD, 2.0%) and 94% for α1-AT, and 50% (RSD, 1.0%) and 90% for Hp. The results demonstrate that this novel multidimensional integrated chromatography system is capable of simultaneously separating multiple protein products from the same raw material with high yield and purity and it has the potential for a wide range of multi-step chromatography separation processes.     

Four divalent metal thiocyanate coordination compounds containing a rigid functional pyridine ligand

A series of new coordination compounds Zn(SCN)₂L₂ (1), Co(SCN)₂L₂ (2), [Cd(SCN)₂L₂·2L]_n (3) and [CdHg(SCN)₄L₂]_n (4) have been prepared by self-assembly of a rigid functional pyridine ligand, trans-4-[4′-(N-methyl-N-hydroxyethyl)amimo]styryl pyridine (abbreviated as L) with M(SCN)_x (M: Zn, Co, Cd, CdHg; x: 2, 4). The crystal structures indicate that 1 and 2 are mononuclear compounds while 3 and 4 are coordination polymers. O–H?N, C–H?O, O–H?π and C–H?π hydrogen bonds play significant roles in the final crystal structures. The solid-state luminescence properties have been measured. The results indicate that the photoluminescence spectra of all the compounds can be changed by the frameworks and introducing of different metal ions.     

Diffusion coefficients of metal acetylacetonates in supercritical carbon dioxide

Binary diffusion coefficients, D₁₂, of the metal acetylacetonates, palladium(II) acetylacetonate and cobalt(III) acetylacetonate, were measured from 308.2 to 343.2 K over the pressure range from 9 to 40 MPa at infinite dilution in supercritical carbon dioxide using the chromatographic impulse response method. The effects of pressure, temperature, density, and viscosity on D₁₂ values were examined. It was observed that the D₁₂ values of palladium(II) acetylacetonate and cobalt(III) acetylacetonate were larger than those of lipids with similar molecular weights, such as arachidonic acid and monoolein, respectively. Furthermore, the measured D₁₂ data of each metal acetylacetonate were well correlated by the hydrodynamic equation D₁₂/T as a function of carbon dioxide viscosity.     

Photoluminescent,liquid‐crystalline,and electrochemical properties of para‐phenylene‐based alternating conjugated copolymers

Novel liquid‐crystalline alternating conjugated copolymers [ P(P(6)CN‐alt‐Cz) and P(P(6)CN‐alt‐MeP) ] with phenylene and carbazolylene or phenylene with methyl substitution onto the main chain have been synthesized through palladium‐catalyzed Suzuki coupling reactions. The influence of the incorporation of carbazolylene and the substituted phenylene into the main chain on the thermal, mesomorphic, and luminescent properties has been investigated by Fourier transform infrared spectroscopy, thermogravimetry, differential scanning calorimetry, polarized optical microscopy, ultraviolet–visible spectroscopy, photoluminescence (PL), and cyclic voltammetry. These polymers show highly thermal stability, losing little of their weights when heated to 360 °C. The conjugated copolymers exhibit liquid crystallinity at elevated temperature. The existence of the chromophoric terphenyl core endows the copolymers with high PL and the polymer P(P(6)CN‐alt‐Cz containing carbazolylene unit can emit more pure blue light. All the copolymer films with low band gaps about 2.3–2.4 eV undergo reversible oxidation and reduction processes, significantly lower than the band gap of poly(p‐phenylene). © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 434–442, 2010